We propose to evaluate the effects of surgery (recession, resection) and local injection of drugs (botulinum toxin, bupivicaine) on the succinylcholine-stimulated extraocular muscle tension (SSMT in grams). There have been no previous attempts to quantify the effects of strabismus therapeutic options on the tonic subsystem, selectively. To this end, we have described a method for the quantification of the SSMT generated in response to a by-weight dose of succinylcholine delivered as a continuous intravenous drip. We seek to apply this method to define the amounts and ratios of SSMT, simultaneously generated within and among antagonist pairs of extraocular muscles (medial vs. lateral), 1) in domestic cats (non-strabismic controls); 2) before and after a fixed amount of recession or resection; 3) before and after the injection of botulinum toxin or bupivicaine; and, 4) to compare the effects of drugs vs. surgery on the SSMT, amounts and ratios, in antagonist muscle pairs. We believe that these data will result in an objective method to quantify and compare the impact of these modalities on the tonic system, and as such, provide a model for the research and development of pharmacologic agents for the attainment of quantitatively similar surgical effects with nonsurgical methods.